Use Arch's grub

johnl · 2012-01-17 22:25:07

I started off running Ubuntu a few years back and installed a copy of Arch on a separate partition to play around with. Well, now I haven't used Ubuntu in two years, but the copy of grub on that installation is still the one controlling things. I'd like to make Arch the base OS and configure grub from here, but I'm not sure how to go about doing this. Where is it determined whose copy of grub is the one that gets booted? If I can change that and copy menu.lst from the Ubuntu installation to Arch's /boot/grub will I get the same working setup?

Sorry for asking such a elementary question -- I could maybe figure it out from Wiki pages, but I've never touched the boot setup before and I'm worried I'll mess things up badly.

kritter · 2012-01-17 23:19:43

An overview of your partitioning would be helpful as well as the information where you installed Ubuntu's or Arch's GRUB (MBR or partition). Does the Ubuntu GRUB chainload Arch's GRUB?

If Ubuntu and Arch use GRUB legacy (the one with menu.lst), you should be able to copy over the menu.lst, but your mileage may vary.

lagagnon · 2012-01-17 23:22:13

What you need is full outlined in our wiki, but does take a bit of reading:
https://wiki.archlinux.org/index.php/Gr … NU.2FLinux

It is really just a matter of running the Arch CD, then running "grub-install".

durian · 2012-01-20 09:37:48

lagagnon wrote:

It is really just a matter of running the Arch CD, then running "grub-install".

I'm in the exact situation as the OP (but Debian, not ubuntu), and I was wondering.

Wouldn't just running "grub-install" from Arch be enough? Even though I choose not to install a bootloader when I installed, I got grub (0.97). The Debian install has grub2.

-peter

debdj · 2012-01-20 19:07:49

It is really just a matter of running the Arch CD, then running "grub-install".

That wont work, AFAK. How would you update the grub.cfg file in arch's /boot/grub?

I think running grub-install from within arch when booted into the actual installation should work. Running update-grub afterwards wont be a pain.

Otherwise, if from a live CD, you should have to mount your / and /boot(if on a different partition) on a temporary dir, mount /dev, /dev/pts, /proc, /sys within the temp dir, chroot into the temp dir and then run grub-install. But that'd be more like a recovery option.

Last edited by debdj (2012-01-20 19:10:32)

durian · 2012-02-02 13:00:30

durian wrote:

I'm in the exact situation as the OP (but Debian, not ubuntu), and I was wondering.
Wouldn't just running "grub-install" from Arch be enough? Even though I choose not to install a bootloader when I installed, I got grub (0.97). The Debian install has grub2.

Just for future reference :-)

I installed grub2 as per grub2 docs (removing grub in the process), from my running arch, and everything went flawless. The only thing I still have to change is the crappy font when displaying the boot info...

-peter

nomorewindows · 2012-02-03 19:25:57

Hold on kids...grub is the same no matter who installed it.
The menu.lst file would be on the Ubuntu installation. All you need to do is get into the Ubuntu's /boot/grub/menu.lst file to include pointing to your Arch Linux installation. No re-installation of grub is necessary. In fact, you can use the grub commandline to boot your arch even if there's no entry for it. (Given you know where it is).

Ideka · 2012-02-05 03:29:59

debdj wrote:

It is really just a matter of running the Arch CD, then running "grub-install".
That wont work, AFAK. How would you update the grub.cfg file in arch's /boot/grub?
I think running grub-install from within arch when booted into the actual installation should work. Running update-grub afterwards wont be a pain.
Otherwise, if from a live CD, you should have to mount your / and /boot(if on a different partition) on a temporary dir, mount /dev, /dev/pts, /proc, /sys within the temp dir, chroot into the temp dir and then run grub-install. But that'd be more like a recovery option.

# mount /dev/sdXA /mnt
# mount /dev/sdXB /mnt/boot
# grub-install --root-directory /mnt /dev/sdX

Ta-dah!
I've done it many times when using a faulty HDD which kept somehow deleting grub.

Although I don't see any problem in doing it within the installed Arch if it can be booted.

Last edited by Ideka (2012-02-05 03:32:18)

Arch Linux

#1 2012-01-17 22:25:07

Use Arch's grub

#2 2012-01-17 23:19:43

Re: Use Arch's grub

#3 2012-01-17 23:22:13

Re: Use Arch's grub

#4 2012-01-20 09:37:48

Re: Use Arch's grub

#5 2012-01-20 19:07:49

Re: Use Arch's grub

#6 2012-02-02 13:00:30

Re: Use Arch's grub

#7 2012-02-03 19:25:57

Re: Use Arch's grub

#8 2012-02-05 03:29:59

Re: Use Arch's grub

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